Hello Kui-Feng Lee,
The patch 539c7e67aa4a: "selftests/bpf: Verify that the cgroup_skb
filters receive expected packets." from Jun 23, 2023 (linux-next),
leads to the following Smatch static checker warning:
./tools/testing/selftests/bpf/prog_tests/cgroup_tcp_skb.c:116 connect_client_server_v6()
warn: unsigned 'addr.sin6_port' is never less than zero.
./tools/testing/selftests/bpf/prog_tests/cgroup_tcp_skb.c
107 static int connect_client_server_v6(int client_fd, int listen_fd)
108 {
109 struct sockaddr_in6 addr = {
110 .sin6_family = AF_INET6,
111 .sin6_addr = IN6ADDR_LOOPBACK_INIT,
112 };
113 int err;
114
115 addr.sin6_port = htons(get_sock_port_v6(listen_fd));
--> 116 if (addr.sin6_port < 0)
^^^^^^^^^^^^^^^^^^
Impossible and also it doesn't make sense to compare network endian data
with < 0.
117 return -1;
118
119 err = connect(client_fd, (struct sockaddr *)&addr, sizeof(addr));
120 if (err < 0) {
121 perror("connect");
122 return -1;
123 }
124
125 return 0;
126 }
regards,
dan carpenter
